Simplify ComponentDescriptor.hashCode() and memoize it

For a very large internal component, saves roughly ~42 seconds on average (or 28%) over 10 runs.

Memoizing the hashCode isn't as stupendous, but profiles do show that memoizing reduces the cost of the hashCode by an additional 10x (after the already big savings): 80ms -> 7ms

RELNOTES=Build performance improvements

-------------
Created by MOE: https://github.com/google/moe
MOE_MIGRATED_REVID=228529245

java/dagger/internal/codegen/ComponentDescriptor.java

@@ -41,6 +41,7 @@
 import com.google.auto.common.MoreElements;
 import com.google.auto.common.MoreTypes;
 import com.google.auto.value.AutoValue;
+import com.google.auto.value.extension.memoized.Memoized;
 import com.google.common.base.Supplier;
 import com.google.common.base.Suppliers;
 import com.google.common.collect.ImmutableBiMap;
@@ -56,6 +57,7 @@
 import dagger.producers.CancellationPolicy;
 import dagger.producers.ProductionComponent;
 import java.util.List;
+import java.util.Objects;
 import java.util.Optional;
 import java.util.stream.Stream;
 import javax.inject.Inject;
@@ -251,6 +253,16 @@ final Optional<CancellationPolicy> cancellationPolicy() {
         : Optional.empty();
   }
 
+  @Memoized
+  @Override
+  public int hashCode() {
+    return Objects.hash(typeElement(), kind());
+  }
+
+  // TODO(ronshapiro): simplify the equality semantics
+  @Override
+  public abstract boolean equals(Object obj);
+
   /** A function that returns all {@link #scopes()} of its input. */
   @AutoValue
   abstract static class ComponentMethodDescriptor {